Annuals and Perennials

What determines if a plant is called a perennial or an annual? A plant that is sold
as an annual is one that completes its life cycle in one season. Think of a impatien, marigold,
or even a tomato plant. We plant them after all chances of frost have passed, then
they grow during the warm months and die with a killing frost. These would be called
warm season annuals—growing from start to finish basically from frost to frost, during
the warmer months of the year. Pansies and violas, lettuce and radishes, would be
considered cool season annuals, with planting dates either in the fall or late winter.
They would die with the onset of hot weather.

Caption (right): Impatiens are an example of a summer annual for the shade.

A perennial is a plant that lives for more than one year. Some perennials like daylilies, asparagus
and hosta die back completely to the ground after a killing frost in the fall, and begin new growth in the spring. Other perennials
like hellebores (Lenten rose), rosemary and lambs ear are evergreen, but live from
year to year. Some perennials are very long lived like peonies and ferns, while others
are relatively short lived like dianthus and foxglove.

Most perennials are non-woody. They have a season of dormancy, and a few are evergreen. They
have a season of bloom, bloom length can vary from 2 weeks to 4 months

Caption (above): Butterfly weed is a sun perennial that blooms in the summer and
attracts butterflies.

Caption (right): Hellebores are a good shade perennial that bloom in early to mid
winter.

Depending on where you live and the average low winter temperature, or high summer
temperature will determine whether the plant is an annual, perennial or evergreen.
Annuals are often used to give you instant color with bedding plants, or as seasonal
vegetables, while perennials may bloom a shorter period of time, but don't have to
be replanted every season.